Vat dye.



crystalline powders with a metallic luster hurrah srarns regress @Ftittfihi WILHELM BAUER, OF VOHWINKEL, AND ALFRED HERRE, OF ELBERFELD, GERMANY, ASSIGNOBS TO EARBENFABRIKEN VORM. FREE DR. BAYER. & 00., 0F ELBERFELD, GERMANY, A. CORPORAEION 0F GERMANY.

VAT DYE.

N 0,1)rawing.

To all whom it may concern: I

Be it known that we, WVILHELM BAUER and ALFRED ,HERRE, doctors of philosophy, chemists, citizens of the German Empire, residing at, respectively, Vohwinkel and Elberfeld, Germany,'l1ave invented new and useful Improvements in Vat Dyes, of which the following is. a specification.

Our invention relates to the manufacture and production of new and valuable vat.

dyestuffs. They are obtained by condensing isatin derivatives in which the oxygen of the alpha-keto group is replaced; by' easily movable or replaceable substituents, c. g. haiogen, sulfur, the amino group, the alkoxy group, with anthrol compounds, especially l-anthrol and its substituted derivatives having a freeortho position to the hydroxy group. v

The new dyes are in a dry state dark blue which are soluble in hot nitrobenzene generally with a blue coloration, and which yield with hydrosultite and caustic soda. lye vats dyeing cotton after exposure to air blue shades remarkable for their fastness to chlorin.

In order to illustrate the new process more fully'we can proceed as follows, the parts being'by weight:

Example 1: 1%.? parts of isatin are con verted in a dry benzene suspension into isatin chlorid by heating it with 21 parts of The mixture thus obtained is then added to a warm solution, which is well stirred, of 20 parts of l-anthrol in drybenzene. After cooling the dye is filtered off and washed with benzene and ether. It is a dark blue powder soluble in cold concentrated sulfuric acid with an olive-green and in hot concentrated sulfuric acid with a greenish-blue color. It forms a vat with hydrosulfite and caustic alkali, from which cotton is dyed after exposure to air in reddish-blue shades.

Example 2: A mixture of 25 parts of para Inethylisatin alpha para toluidid, '20 parts of l-anthrol and 100 parts of acetic acid anhydrid is heated on the water-bath until the formation of the dye is complete. The .dye which separates in crystals is filtered ed and washed. It crystallizesin blue bluish-green color.

Specification of Letters Patent. Patented J 11111.3 14, 1919,

Application filed September 8, 1909.

Serial No. 516,686.

needles with a copper luster and is soluble 1n cold concentrated sulfuric acid with a It dyes cotton from a hydrosulfite vat after exposure to air deep greenish-blue shades.

Example 3: 100 parts of dibronioisatin are converted in a dry benzene suspension into dibromoisatin chlorid by heating it with '72 parts of P01 The mixture thus obtained is then poured into a solution which is well stirred of parts of l-anthrol in dry benzene. The stirring is continued for a shorttime and the dye which separates on cooling is filtered OH and washed. It is a dark blue crystalline powder with a copper luster scarcely soluble in hot benzene with a greenish-blue and in concentrated sulfuric acid with an oli e color. It yields with hydrosulfite and NaOH an orangeyellow vat from ,which cotton is dyed orange-yellow changing on exposure to air into a fast deep greenish-blue fast to 'ch-lorin.

Other anthrol derivatives may be used,

c. g. 1.5- and 1.8-dioxyanthracene; and instead of the above isatin derivatives others.

may be used, c. g. chloro-, bron'io-, chlorobromoor dicliloroisatin chlorid, orthobronio-para-n'iethyl-isatinchlorid,trl-broinoisatin chlorid, ortho-methylisatin chlorid,

ortho paradiniethylisatin chlorid, parabromo-ortho-niethlyisatin chlorid etc. etc.

lle claim 1. The herein-described new dyestufl sobtainable froman isatin derivative in which the oxygen of the alpha-lreto group is replaced by easily movable or replaceable substituents and a hereinbefore defined l-anthrol compound, which dyestuiis are in a dry state dark blue crystalline powders with a metallic luster which are soluble in hot nitrobenzcne generally with a blue colora-.

tion, and which yield with h'ydrosulfite and caustic soda lye vats dyeing cotton after exposure to air blue shades.remarkable for their fastness to chlorin, substantially as described.

2. The herein-described new dyestuff obtainable from dibromoisatin-alpha-chlorid and l-anthrol, which dyestufi is in a dry state a dark blue crystalline powder with a copper luster, scarcely soluble in hot benzene with a greenish-blue and in concen- I trated sulfu ic acid with an olive 06101, and set our hands in the presence of two sub- Which yields with 'hydrosulfite and caustic scribing witnesses.

soda lye an orange yellow 'vat from which WILHELM BAUER [L 81 cotton is dyed orange-yellow chem ing on T I exposure to air into a deep greez sh-blue ALFRED IIERRE' remarkable for its fastness to chlorin, sub- Witnesses: stantially as described. O'ITO Kijme,

In testimony whereof we have hereunto v WILLY. KLEIN. 

